Proxmox VE kernel compat, invalidate_inodes()

The Proxmox VE kernel contains a patch which renames the function
invalidate_inodes() to invalidate_inodes_check().  In the process
it adds a 'check' argument and a '#define invalidate_inodes(x)'
compatibility wrapper for legacy callers.  Therefore, if either
of these functions are exported invalidate_inodes() can be
safely used.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #58

config/spl-build.m4

@@ -1816,6 +1816,13 @@ dnl # The function invalidate_inodes() is no longer exported by the kernel.
 dnl # The prototype however is still available which means it is safe
 dnl # to acquire the symbol's address using spl_kallsyms_lookup_name().
 dnl #
+dnl # The Proxmox VE kernel contains a patch which renames the function
+dnl # invalidate_inodes() to invalidate_inodes_check().  In the process
+dnl # it adds a 'check' argument and a '#define invalidate_inodes(x)'
+dnl # compatibility wrapper for legacy callers.  Therefore, if either
+dnl # of these functions are exported invalidate_inodes() can be
+dnl # safely used.
+dnl #
 AC_DEFUN([SPL_AC_KERNEL_INVALIDATE_INODES], [
 	SPL_CHECK_SYMBOL_EXPORT(
 		[invalidate_inodes],
@@ -1823,6 +1830,12 @@ AC_DEFUN([SPL_AC_KERNEL_INVALIDATE_INODES], [
 		[AC_DEFINE(HAVE_INVALIDATE_INODES, 1,
 		[invalidate_inodes() is available])],
 		[])
+	SPL_CHECK_SYMBOL_EXPORT(
+		[invalidate_inodes_check],
+		[],
+		[AC_DEFINE(HAVE_INVALIDATE_INODES_CHECK, 1,
+		[invalidate_inodes_check() is available])],
+		[])
 ])
 
 dnl #

configure

@@ -15638,6 +15638,45 @@ _ACEOF
 
 	fi
 
+	{ $as_echo "$as_me:$LINENO: checking whether symbol invalidate_inodes_check is exported" >&5
+$as_echo_n "checking whether symbol invalidate_inodes_check is exported... " >&6; }
+	grep -q -E '[[:space:]]invalidate_inodes_check[[:space:]]' \
+		$LINUX_OBJ/Module*.symvers 2>/dev/null
+	rc=$?
+	if test $rc -ne 0; then
+		export=0
+		for file in ; do
+			grep -q -E "EXPORT_SYMBOL.*(invalidate_inodes_check)" \
+				"$LINUX_OBJ/$file" 2>/dev/null
+			rc=$?
+		        if test $rc -eq 0; then
+		                export=1
+		                break;
+		        fi
+		done
+		if test $export -eq 0; then
+			{ $as_echo "$as_me:$LINENO: result: no" >&5
+$as_echo "no" >&6; }
+
+		else
+			{ $as_echo "$as_me:$LINENO: result: yes" >&5
+$as_echo "yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_INVALIDATE_INODES_CHECK 1
+_ACEOF
+
+		fi
+	else
+		{ $as_echo "$as_me:$LINENO: result: yes" >&5
+$as_echo "yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_INVALIDATE_INODES_CHECK 1
+_ACEOF
+
+	fi
+
 
 	{ $as_echo "$as_me:$LINENO: checking whether invalidate_inodes() wants 2 args" >&5
 $as_echo_n "checking whether invalidate_inodes() wants 2 args... " >&6; }
@@ -19908,6 +19947,45 @@ _ACEOF
 
 	fi
 
+	{ $as_echo "$as_me:$LINENO: checking whether symbol invalidate_inodes_check is exported" >&5
+$as_echo_n "checking whether symbol invalidate_inodes_check is exported... " >&6; }
+	grep -q -E '[[:space:]]invalidate_inodes_check[[:space:]]' \
+		$LINUX_OBJ/Module*.symvers 2>/dev/null
+	rc=$?
+	if test $rc -ne 0; then
+		export=0
+		for file in ; do
+			grep -q -E "EXPORT_SYMBOL.*(invalidate_inodes_check)" \
+				"$LINUX_OBJ/$file" 2>/dev/null
+			rc=$?
+		        if test $rc -eq 0; then
+		                export=1
+		                break;
+		        fi
+		done
+		if test $export -eq 0; then
+			{ $as_echo "$as_me:$LINENO: result: no" >&5
+$as_echo "no" >&6; }
+
+		else
+			{ $as_echo "$as_me:$LINENO: result: yes" >&5
+$as_echo "yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_INVALIDATE_INODES_CHECK 1
+_ACEOF
+
+		fi
+	else
+		{ $as_echo "$as_me:$LINENO: result: yes" >&5
+$as_echo "yes" >&6; }
+
+cat >>confdefs.h <<\_ACEOF
+#define HAVE_INVALIDATE_INODES_CHECK 1
+_ACEOF
+
+	fi
+
 
 	{ $as_echo "$as_me:$LINENO: checking whether invalidate_inodes() wants 2 args" >&5
 $as_echo_n "checking whether invalidate_inodes() wants 2 args... " >&6; }

include/linux/mm_compat.h

@@ -54,7 +54,7 @@
  * As for 2.6.39 invalidate_inodes() was updated to take a second
  * argument which controls how dirty inodes should be handled.
  */
-#ifdef HAVE_INVALIDATE_INODES
+#if defined(HAVE_INVALIDATE_INODES) || defined(HAVE_INVALIDATE_INODES_CHECK)
 # ifdef HAVE_2ARGS_INVALIDATE_INODES
 #  define spl_invalidate_inodes(sb, kd)	invalidate_inodes(sb, kd)
 # else
@@ -70,7 +70,7 @@ typedef int (*invalidate_inodes_t)(struct super_block *sb);
 extern invalidate_inodes_t invalidate_inodes_fn;
 #  define spl_invalidate_inodes(sb, kd)	invalidate_inodes_fn(sb)
 # endif /* HAVE_2ARGS_INVALIDATE_INODES */
-#endif /* HAVE_INVALIDATE_INODES */
+#endif /* HAVE_INVALIDATE_INODES || HAVE_INVALIDATE_INODES_CHECK */
 
 #if !defined(HAVE_SHRINK_CONTROL_STRUCT)
 struct shrink_control {

module/spl/spl-kmem.c

@@ -180,10 +180,10 @@ spl_global_page_state(spl_zone_stat_item_t item)
 #endif /* NEED_GET_ZONE_COUNTS */
 EXPORT_SYMBOL(spl_global_page_state);
 
-#ifndef HAVE_INVALIDATE_INODES
+#if !defined(HAVE_INVALIDATE_INODES) && !defined(HAVE_INVALIDATE_INODES_CHECK)
 invalidate_inodes_t invalidate_inodes_fn = SYMBOL_POISON;
 EXPORT_SYMBOL(invalidate_inodes_fn);
-#endif /* HAVE_INVALIDATE_INODES */
+#endif /* !HAVE_INVALIDATE_INODES && !HAVE_INVALIDATE_INODES_CHECK */
 
 #ifndef HAVE_SHRINK_DCACHE_MEMORY
 shrink_dcache_memory_t shrink_dcache_memory_fn = SYMBOL_POISON;
@@ -2113,14 +2113,14 @@ spl_kmem_init_kallsyms_lookup(void)
 	 */
 	spl_kmem_init_globals();
 
-#ifndef HAVE_INVALIDATE_INODES
+#if !defined(HAVE_INVALIDATE_INODES) && !defined(HAVE_INVALIDATE_INODES_CHECK)
 	invalidate_inodes_fn = (invalidate_inodes_t)
 		spl_kallsyms_lookup_name("invalidate_inodes");
 	if (!invalidate_inodes_fn) {
 		printk(KERN_ERR "Error: Unknown symbol invalidate_inodes\n");
 		return -EFAULT;
 	}
-#endif /* HAVE_INVALIDATE_INODES */
+#endif /* !HAVE_INVALIDATE_INODES && !HAVE_INVALIDATE_INODES_CHECK */
 
 #ifndef HAVE_SHRINK_DCACHE_MEMORY
 	/* When shrink_dcache_memory_fn == NULL support is disabled */

spl_config.h.in

@@ -111,6 +111,9 @@
 /* invalidate_inodes() is available */
 #undef HAVE_INVALIDATE_INODES
 
+/* invalidate_inodes_check() is available */
+#undef HAVE_INVALIDATE_INODES_CHECK
+
 /* kallsyms_lookup_name() is available */
 #undef HAVE_KALLSYMS_LOOKUP_NAME